In recent years, in addition to codes and passwords that are combinations of letters and symbols, research and development in the biometric authentication technology of performing authentication by using physical features of a target person is being performed. In performing biometric authentication, physical features such as fingerprints, dorsal hand vein patterns, the iris patterns of eyes, voice prints, and the like that are not uniform among individuals are typically used. Particularly, as authentication accuracy improves, and the cost of devices comes down, authentication devices that use fingerprints or dorsal hand vein patterns are starting to be used in various kinds of devices such as an ATM (Automatic Teller Machine) or a personal computer (PC).
However, in authentication using fingerprints or dorsal hand vein patterns, the target person must bring part of the body such a finger or hand in contact with or close to the device. Therefore, recently biometric authentication technology that uses the iris pattern of an eye is gaining much attention (for example, refer to Patent Literature 1).